1. Field of the Invention
This invention is in the field of devices and methods for testing the visual field characteristics of a patient.
2. Background Art
Visual field testing remains the "gold standard" for diagnosing diseases of the optic nerve and the visual system. Ideally, a visual field testing system would objectively measure the visual field of a patient without any subjective response whatsoever on the part of the patient. However, currently known visual field examinations require great concentration on the part of the patient and can be tedious and frustrating to the point of annoyance. Current techniques involve a globe-type visual field tester, called a "perimeter," such as those manufactured by Humphrey Instruments, Dicon, Octopus, and others. These conventional visual field testers generally require that a patient continuously fixate upon a central point, while lights are displayed sequentially into the peripheral field. When the patient sees the light out of the corner of the eye in the peripheral visual field, the patient responds by pressing a button, or responding verbally, all the while being strictly required to maintain central fixation. Generally, central gaze must be maintained without interruption for up to 10 minutes. This requires maximal concentration by the patient.